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Biomedical subjects

A Lavergne

Publications and source records attributed to A Lavergne.

At least 73 records · Page 4Linked to original sources
PubMed1985

Vascular evolution of single-layer end-on colonic anastomosis. A microangiographic study of 180 anastomoses in the rat from two to 180 days.

One hundred eighty left colonic single-layer end-on anastomoses performed on 90 rats by microsurgical techniques, using polydioxanone monofilament absorbable sutures, were examined histopathologically and microangiographically at nine different times, from two to 180 days. There was no anastomotic leakage. The vascular state after suturing and the evolution of the neovascularization are described. The neovascularization appeared to follow the same process of evolution as tissue restoration. It began early, was greatest on the seventh day, and diminished thereafter. When granulation tissue was narrow, the anastomoses were barely hypervascular, the neovascularization assured by submucosal plexus. A voluminous granulation tissue was hypervascular, had a slower evolution, and neovascularization was then assured above all by the peritoneal formations adherent to the suture.

Animals↗
PubMed1985

Occurrence of a new microsporidan: Enterocytozoon bieneusi n.g., n. sp., in the enterocytes of a human patient with AIDS.

A new microsporidium is reported infesting the enterocytes of a Haitian patients with AIDS. The stages observed were diplokaryotic cells, sporogonial plasmodia, unikaryotic sporoblasts, and spores. Neither a sporophorous vesicle (pansporoblastic membrane) nor parasitophorous vacuole were differentiated around the developmental stages, which were in direct contact with the host cell cytoplasm. The polar tube (5-6 coils) was differentiated before fission of the sporogonial plasmodium. The mature spores measured 1.5 micron X 0.5 micron. The spore wall was very thin as the endospore was absent or poorly differentiated. The organism is named Enterocytozoon bieneusi n. g., n. sp. and is assigned to the suborder Apansporoblastina.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Diarrhoea and malabsorption in acquired immune deficiency syndrome: a study of four cases with special emphasis on opportunistic protozoan infestations.

Chronic diarrhoea is frequent in acquired immune deficiency syndrome (AIDS) but has been poorly investigated so far. We report four patients with AIDS in whom diarrhoea and malabsorption were outstanding features, and who underwent extensive digestive investigations. Diarrhoea was a presenting symptom in all subjects and was of secretory type in three of them. D-xylose and vitamin B12 were malabsorbed in all cases; steatorrhea was found in the two patients who could ingest significant amounts of fat. Faecal alpha 1-antitrypsin clearance was increased in all subjects. Search for digestive pathogens showed unusual protozoans in all patients: in case 1, optical and electron microscopy revealed the presence in the cytoplasm of villous enterocytes of Microsporidia protozoans still unreported in AIDS. Stool and jejunal fluid examination showed Isospora belli in case 2 and Cryptosporidium in cases 3 and 4. On histological and ultrastructural study the former was localised in the cytoplasm of a few enterocytes and the latter was scattered throughout the villus and crypt brush border. Otherwise small intestinal histology only showed minor non-specific changes and the enterocytes were ultrastructurally normal. In patient 3 the slow marker intestinal perfusion technique showed a profuse fluid secretion in the duodenum and proximal jejunum. All patients needed prolonged total parenteral nutrition. Cryptosporidium and Microsporidia could not be eradicated despite multiple drug trials. Isospora belli was transiently cured by pyrimethamine-sulphadiazine. Only patient 2 is presently at home, and patients 1, 3, and 4 died after two, six, and nine months of total parenteral nutrition, respectively.

Acquired Immunodeficiency Syndrome↗
PubMed1985

[In vitro opening of human atheromatous coronary arteries using a pulsed laser].

This study was undertaken to assess the respective values of pulsed and continuous laser emission for in vitro recanalisation of very stenosed atheromatous human coronary arteries. The Nd-YAG laser used emitted a 10 Hz 10 ns burst in the infrared band (1 064 microns). Previous spectroscopic studies had shown no specific band of absorption in the spectral field of emission of the usual lasers. The laser beam was focused in the axis of the segment of coronary artery irradiated. The crater or neo lumen obtained usually had irregular walls. No perforation of the arterial wall or macroscopic debris were observed. Histological studies showed minimal burn lesions with sparse coagulation necrosis limited to a few tens of micron thickness. The percentage recanalisation obtained with pulses of 200 mJ attained 50% for a total energy of 450 J delivered in 2 mn. This study confirmed the feasibility of disobliteration of atheromatous coronary arteries by pulsed laser. Our results suggest that ultra short pulsed laser acts more by a mechanical than by a thermal mechanism which may lead to less side effects than observed in vivo with continuous laser emission.

Coronary Disease↗
PubMed1984

Reduction of myocardial infarct size by a fluorocarbon-oxygenated reperfusate.

This investigation assesses whether the size of an acutely revascularized myocardial infarct (MI) could be reduced by altering the composition of the initial reperfusate. Nineteen open-chest dogs underwent 4-hour occlusion of the left anterior descending coronary artery and were then assigned to a treatment group: 12 dogs to selective intracoronary infusion of the modified reperfusate over 30 minutes before resumption of blood flow for 60 minutes and 7 to a control group (90 minutes of unmodified blood reperfusion). The modified reperfusate consisted of 500 ml of a fluorocarbon-oxygenated crystalloid solution (PO2 650 mm Hg; total O2 content 5.5 vol%) whose composition was adjusted by decreasing Ca++ (0.25 mM), increasing pH (7.60) and adding glucose (1.8 g/liter). Four hours after occlusion, technetium-99m-labeled microspheres were injected into the left atrium. After 90 minutes of reperfusion, the heart was removed and sliced transversely. Areas not perfused by microspheres (areas at risk) were traced, planimetered and compared with the areas of necrosis after incubation in triphenyltetrazolium chloride. Areas were then converted into weights. In control dogs, the weight of necrotic myocardium was not significantly different from the weight at risk (5.0 +/- 0.7 vs 7.0 +/- 0.8 g, respectively [mean +/- standard error of the mean]), whereas it was markedly reduced in treated dogs (5.9 +/- 0.5 vs 9.4 +/- 0.7 g, respectively, p less than 0.001). The weight of salvaged myocardium was 3.4 +/- 0.5 g in treated dogs vs 1.9 +/- 0.4 g in the control group (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

[Hyperparathyroidism secondary to renal insufficiency: anatomo-clinical relations and the potential role of an aluminum overload].

Severe secondary hyperparathyroidism is still observed at present in 5-10% of haemodialysis patients. It requires surgical correction. Fifty-eight haemodialysis patients had neck surgery and their 222 parathyroid glands analysed. The individual gland weight was comprised between 22 and 3880 mg (mean +/- SEM, 689 +/- 62 mg). Mean total parathyroid gland weight per patient was comprised between 2 and 3 g. Schematically, 4 types of gland architecture could be distinguished: diffuse hyperplasia alone; diffuse hyperplasia associated with incipient nodule formation; hyperplasia with pronounced nodule formation; and nodule formations alone. Total gland weight was significantly higher for the latter two histological forms than for the former suggesting transformation with time of pure hyperplasia to nodular hyperplasia. Patients with chronic pyelonephritis had a mean gland weight higher than that of patients with chronic glomerulonephritis (3308 +/- 498 mg versus 1824 +/- 358 mg, p less than 0.01). No relation was found between total gland weight and plasma calcium, phosphate or alkaline phosphatases. However, a weak relation existed between total gland weight and plasma immunoreactive parathyroid hormone. In addition, a negative relation was observed between highest prior plasma aluminium and gland weight when considering only patients with a gland weight less than 2000 mg. Parathyroid gland aluminium content was significantly higher in haemodialysis patients than in nonuraemic patients with primary hyperparathyroidism. A direct relation was found between parathyroid gland and bone aluminium. In conclusion, in haemodialysis patients with evolving hyperparathyroidism initially diffuse gland hyperplasia appears to be associated progressively with nodule formation. Circulating immunoreactive parathyroid hormone is positively related to total gland weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

[Primary biliary cirrhosis and sarcoidosis. Association or unique disease?].

The incontestable simultaneous occurrence of primary biliary cirrhosis and sarcoidosis is reported in a 40 year-old woman. The diagnosis of primary biliary cirrhosis was based on the association of intrahepatic cholestasis, increased serum IgM, high titer of antimitochondrial antibodies and hepatic histologic lesions. In six years the latter passed from bile duct destruction with fibrosis to cirrhosis with absence of bile ducts. The diagnosis of sarcoidosis relied on the presence of bilateral hilar lymphadenopathies, pulmonary infiltrate, tuberculoid granuloma without necrosis in an enlarged cervical lymph node and increased serum level of angiotensin conversion enzyme improved by steroid therapy. Such an association, only three other cases of which have been reported, suggests a link between the two diseases, which could be two localizations of a same physiopathological process.

Adult↗
PubMed1984

[Giant fibroma of the pleura. Apropos of 2 cases].

Two cases are reported of giant pleural fibroma (2.9 and 4.2 kg), of slow growth (both had been present for 17 years), developing in the parietal pleura in a 56-year-old woman and in the triangular ligament of a 35-year-old man respectively, and treated by surgical excision. Findings in these cases and data on those reported in the literature indicate the principal pathologic and clinical characteristics of these very rare benign tumors of the pleura: onset in the absent of any history of exposure to dust (asbestos); usually fortuitous discovery; suggestive radiological appearances (calcification in some cases) that are not pathognomonic however; differentiation from fibrous mesothelioma by the microscopic or particularly gross pathologic appearance; treatment exclusively surgical and of variable difficulty according to the size of and especially the structures related to the tumor, with the need for careful preoperative screening.

Adult↗
PubMed1983

[Multiple lesions in primary hyperparathyroidism. Nosologic approach].

Surgical exploration identified 40 patients with several enlarged parathyroid glands (two to five) out of a retrospective series of 500 cases of primary hyperthyroidism. Complete clinicopathological correlations were available in 27 cases (19 women and 8 men). Seven patients had a history of Wermer's syndrome (type I, MEN). Final diagnosis was as follows: double adenomas, 11 cases; primary hyperplasia, 16 cases. In two cases, there was a clear-cell hyperplasia, 16 cases. In two cases, there was a clear-cell hyperplasia with massive involvement of four parathyroid glands. The fourteen other cases presented with predominantly chief-cell hyper plasia; the involvement of the parathyroid glands was frequently asymmetrical, mainly or exclusively confined to two enlarged glands in 9 cases. The authors conclude that when a patient presents with two enlarged parathyroid glands, two diagnoses are possible--double adenoma or asymmetrical hyperplasia. Since anatomical study of the two enlarged glands is not always sufficient for accurate classification of the lesions, it is advisable to make a histological examination of a third.

Adenoma↗
PubMed1983

[Anatomo-pathological evolution of single-layer end-to-end digestive anastomoses. A study of 210 colonic anastomoses in rats from the 2d to the 180th day].

Two hundred and ten left colonic single-layer end-to-end anastomoses (105 by extramucosal continuous suture, 53 by extramucosal interrupted sutures, 52 by total continuous suture) performed on 105 rats with microsurgical techniques using a slowly resorbed suturing material were examined histologically at nine different times between the 2nd and the 180th days. The histopathological evolution of the inflammatory granuloma, the granulation tissue, the reepithelialization process and the restoration of the smooth muscle layers are described. The rate and the amount of inflammation were found to differ between animals and three different types of evolution could be schematized. The differences could not be due to the suturing techniques since continuous and interrupted sutures gave the same results, but rather to the manner of treating the intestinal cut edges before and during suturing. The amount of inflammation was found to decrease with the operator's training.

Animals↗
PubMed1983

Secondary hyperparathyroidism in chronic haemodialysis patients: a clinico-pathological study.

Fifty-eight patients on intermittent haemodialysis underwent parathyroidectomy because of severe secondary hyperparathyroidism. Mean individual parathyroid gland weight was 689 +/- 62 (SEM) mg. Mean total gland weight per patient was between two and three grams. Increasing nodule formation within hyperplastic glands appeared to develop with increasing time of duration of hyperparathyroidism. Patients with chronic pyelonephritis had a higher gland weight than those with chronic glomerulonephritis. A direct relationship was found between gland weight and circulating immunoreactive parathyroid hormone, but an inverse relationship between gland weight and plasma aluminium concentration. The higher the parathyroid gland aluminium, the higher was the bone aluminium concentration.

Adolescent↗
PubMed1982

[Unexpected generalized amyloidosis discovered on biopsies. Value of Wright's method for etiologic diagnosis. Three case-reports].

Three cases are reported in which unexpected generalized amyloïdosis was disclosed by biopsies. The authors emphasize the value of precise analysis of the deposits and particularly of Wright's method for studying their staining properties. This method can guide investigations towards one of the two main etiologies of amyloïdosis (immunoglobulinic or AA).

Aged↗
PubMed1982

[Digestive amyloidosis in generalized amyloidosis. Current data and practical applications (author's transl)].

Following a summary of the modern, biochemical classification of generalized amyloidosis into immunoglobulin-induced (AL) and non immunoglobulin-induced (AA), the authors study amyloid lesions of the digestive tract. The classical topographical data concerning primary and secondary amyloidosis are described. These data are confirmed by current studies based on the new classification and completed by a technique recently developed by Wright, where treatment of histological sections with potassium permanganate makes it possible to differentiate AL amyloidosis from AA amyloidosis. The resulting practical classification of amyloid deposits enables clinicians to form an idea of the aetiological group concerned. A study of rectal biopsies emphasizes the value of the results. The special cases of Portuguese amyloidosis and amyloidosis associated with Crohn's disease are also studied.

Amyloid↗